President Barack Obama said Wednesday it was in America's interest to have "constructive" ties with Russia, but admitted the relationship had reverted to an "adversarial spirit" when Vladimir Putin regained the presidency.

"I think it's in America's interest and the world's interest that we have a constructive relationship with Russia. That's been my approach throughout my presidency," Obama said at his final press conference before handing power to Donald Trump.

But he said that when Putin began his second stint as Russian president in 2012, "escalating anti-American rhetoric" led to a more "adversarial spirit" which "has made the relationship more difficult."

Trump has said he plans to make improving ties with Russia a priority. US intelligence agencies have concluded that Moscow interfered in the November election with the aim of tipping the scales in the Republican's favor.